A better way to drill acrylics

[The Snark]

Granted: Drill bits can work. However, they are inclined planes. Read, wedges. You force them into the material and as they turn they try to spread the material out as they cut.

A much better way to go: Check with shops that supply machinists tools and buy an End Mill of the appropriate size you can chuck into your drill.

End mills do not wedge. They have cutting surfaces across the entire end as well as sides. While they are more expensive, with proper care taken they will cut clean holes in even the most brittle plastics.

 

[Ratmosphere]

Thanks for the tips!

 

[viper69]

You can buy a single fluted drill bit designed specifically for acrylic for about 6-8$ from Tap Plastics.

 

[Red Eunice]

Yes, those will work, but the average hobbiest wants "cheap".

Mill bits, used in a hand drill will skate around due to their flat leading edge. On a drill press the stock must be securely held in place and sacrificial material underneath to avoid chipping. Plus the material has to be repositioned to drill each hole. A tedious task most won't want to undertake, they prefer "fast".

@viper69 I didn't see the single flute bits on Tap's website using their "search" option. Several sizes w/h 2 flutes, PlasDrill on the package label, showed up though. Those should work equally well, depending on rpms used, avoiding the material melting. I bought 3 flute bits from a local HVAC supply house, cheap $4-6 each, 960 rpm on the drill press produced clean holes and no chipping. Using a drill press, proper rpm and pressure are key for best results.

 

[SDCPs]

End mill! That's what I've been missing all this time. No more broken plastic, thanks man!

 

[viper69]

Yes, those will work, but the average hobbiest wants "cheap".

Mill bits, used in a hand drill will skate around due to their flat leading edge. On a drill press the stock must be securely held in place and sacrificial material underneath to avoid chipping. Plus the material has to be repositioned to drill each hole. A tedious task most won't want to undertake, they prefer "fast".

@viper69 I didn't see the single flute bits on Tap's website using their "search" option. Several sizes w/h 2 flutes, PlasDrill on the package label, showed up though. Those should work equally well, depending on rpms used, avoiding the material melting. I bought 3 flute bits from a local HVAC supply house, cheap $4-6 each, 960 rpm on the drill press produced clean holes and no chipping. Using a drill press, proper rpm and pressure are key for best results.

My man, can't trust a search bar hehe

https://www.tapplastics.com/product/supplies_tools/plastic_tools_supplies/tap_plasdrill_bits/161

 

[sdsnybny]

The drill bits on Tap Plastics web site work very well. the tip is ground at 60 degrees as opposed to the normal drill bits 30 degree angle, that along with the single steeper flute are the trick. Quick clean holes, no chipping. and can be drilled without backing/sacrificial material.

 

[The Snark]

End mill drilling with a hand held drill. You need an end mill of the appropriate size, a ~2 inch thick metal block and a metal ruler.
Grind off the cutting surfaces on the side of the end mill then use it to drill a hole squarely through the metal block.
Place the acrylic on a flat board.
Add a light coating of grease to the side of the end mill.
Now clamp your metal ruler to the acrylic. Place the metal block square against the ruler and hold firmly. Drill/Mill through the metal block, incrementing along the ruler for perfect neat rows of holes.

With a drill press, clamp the metal ruler to the bed and move the acrylic along it.

 

[Chris LXXIX]

I suggest the 'drill methods' of Rocco Siffredi and John Holmes (R.I.P). Nothing resisted that screwing

 

[The Snark]

One trick end mills are especially good at.

Use the above metal block but drill the guide hole in it at a 45 degree angle. Keep all holes angled in the same direction. Now place a whisper fan on top of the enclosure with an appropriate mesh screen in front of it, sucking the air out. The angled holes will force the incoming air to circulate. With careful placement of the holes you can eliminate dead zones like where mold tends to grow.

 

[The Snark]

In the world of precision machinists, drill bits are only used for rough in work. End mills and reamers are always the tools of choice.

 

[Chris LXXIX]

Seriously now, you can use this as well:
http://www.thespidershop.co.uk/hole-jabber-p-3474.html

I have one, and those things are really sharp :-s

 

[Red Eunice]

My man, can't trust a search bar hehe

https://www.tapplastics.com/product/supplies_tools/plastic_tools_supplies/tap_plasdrill_bits/161

That's the bits I saw, time to see the optometrist again. Lol!

 

[The Snark]

Rotabroach v drill bits. Highly informative.

The advantage is a broach puts almost no stress upon the materials.